exxos's Atari, Amiga & retro forum

Forgottenmyname wrote: 18 Sep 2018 21:42 Ok, so all three ROM1,2,3 inputs have to be high to disable the /OE on the ROM. Can you think of any reason that the GLUE is disabling the ROM?

GLUE will disable the ROM when its not accessing it.. After reset you will see OE go low (or should do) because the CPU will read the first bytes in ROM to start running code... So I would check you see that first pulse low...

I think it was you who fitted the rom socket in wrong way ? That could be why your not getting as far as Icky if the ROM isn't making good contact in the socket, which I assume it isn't...

Unfortunately guilty as charged. Everything looks lined up ok but will meter it later on when I get home

So, had a good look at the socket for the ROM and I'm sure that one whole side is not quite lining up properly, so will bite the bullet and turn it the right way round. (I'd modified the notches on the socket before for my mistake instead of just unsoldering etc.

Forgottenmyname wrote: 19 Sep 2018 19:31 So, had a good look at the socket for the ROM and I'm sure that one whole side is not quite lining up properly, so will bite the bullet and turn it the right way round. (I'd modified the notches on the socket before for my mistake instead of just unsoldering etc.

:)

Might be a idea to fit a new socket...

Hopefully then you can get bombs up like Icky.. but as your video is stable.. maybe will be able to look at the next issues then...

Didn't have a new socket but pretty sure everything is making contact now.

I did have /halt low when I restarted, so will check the socket connections tomorrow for poorly soldered joints.

Gained Desoldering +1 tonight. Have finally cracked the art of good Desoldering.... top tip patience and a whole load of flux.

So, update 1 for today.

Changed the MFP to rule it out, no difference.

What is happening is that /BERR is now going low once every 100us which I think is why I wont get the 50hz output on the Glue. So I removed the Glue and /BERR stays high, Obviously Glue pulsing it low at times.

Now to work out why the Glue isn't happy.

Do you see /AS pulse low after reset ?

If I hold reset then /AS goes high but then back to 1Mhz square wave

Forgottenmyname wrote: 20 Sep 2018 18:02 If I hold reset then /AS goes high but then back to 1Mhz square wave

I have seen that happen before but don't really know what causes it... Can you capture /AS & /DTACK ?